Cass City, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.8 °C (low) to 13.4 °C (high). Annual precipitation averages 835.7 Millimeters. Cass City is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.6 °C | -1.6 °C | 50.04 mm |
| February | -9.6 °C | -0.2 °C | 41.15 mm |
| March | -5 °C | 5.2 °C | 47.5 mm |
| April | 0.8 °C | 12.6 °C | 85.85 mm |
| May | 7.1 °C | 19.4 °C | 89.41 mm |
| June | 12.6 °C | 25.1 °C | 88.39 mm |
| July | 14.8 °C | 27.2 °C | 80.01 mm |
| August | 14.2 °C | 26.1 °C | 84.07 mm |
| September | 10.1 °C | 22.7 °C | 78.23 mm |
| October | 4.5 °C | 15.3 °C | 76.45 mm |
| November | -0.8 °C | 7.7 °C | 63.25 mm |
| December | -5.6 °C | 1.4 °C | 51.31 mm |
| Annual | 2.8 °C | 13.4 °C | 835.66 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |